1. Field of the invention
The present invention relates to a process for the manufacturing of decorative boards with a decorative upper surface.
2. Background of the Invention
Products clad with thermosetting laminate is common in many areas nowadays. They are mostly used where the demands on abrasion resistance are high, and furthermore where resistance to different chemicals and moisture is desired. As examples of such products floors, floor skirtings, table tops, work tops and wall panels can be mentioned.
The thermosetting laminate most often consist of a number of base sheets with a decor sheet placed closest to the surface. The decor sheet can be provided with a pattern by desire. Common patterns usually visualize different kinds of wood or mineral such as marble and granite. Also fantasy based decor and monochrome decor are rather common.
When manufacturing laminate boards comprising thermosetting laminate the process normally includes the steps; printing decor on a paper of α-cellulose, impregnating the decorative paper with melamine-formaldehyde resin, drying the decorative paper, laminating the decorative paper under heat and pressure together with similarly treated supporting papers, applying the decorative laminate on a carrier and finally sawing and milling the carrier to the desired format. All these steps in the manufacturing are very time consuming and will cause waste of the thermosetting laminate. The thermosetting laminate is a rather costly part of a laminate floor.
Another problem with thicker laminates with a core of particle board or fiber board is that these normally will absorb a large amount of moisture, which will cause them to expand and soften whereby the laminate will warp. The surface layer might even, partly or completely come off in extreme cases since the core will expand more than the surface layer. This type of laminate can therefore not be used in humid areas, such as bath rooms or kitchens, without problem.
The problems can be partly solved by making the core of paper impregnated with thermosetting resin as well. Such a laminate is most often called compact laminate. These compact laminates are, however, very expensive and laborious to obtain as several tens of layers of paper have to be impregnated, dried and put in layers.